Abstract: A spiral step twist drill bit, including a shank and a cutting portion. The cutting portion is provided with a spiral flute and a body clearance. A tip of the cutting portion is provided with a chisel edge and a cutting edge. A flank face is connected to the cutting edge, and is provided with a spiral cutting groove. A spiral direction of the spiral cutting groove is the same as that of the spiral flute. A slope of the spiral cutting groove is the same as that of the flank face. The spiral cutting groove is configured to divide the cutting edge into multiple segments to form multiple first edges and second edges.